PG&E: Some heat waves too much for transformers

Equipment in cooler areas particularly susceptible to temps that soar over 100

PG&E transformers in the Bay Area can’t always cope with heat waves of the type scorching Northern California this week, the utility said Tuesday.

The assessment from PG&E arrived amid a heat wave that has roasted the Bay Area and helped to trigger power outages that knocked out service to 26,400 PG&E customers in the nine-county region on Monday.

“Monday was one of the hottest days on the books,” PG&E spokesman Jeff Smith said. “Transformer failures are usually caused when the temperatures are too great for the equipment.”

Transformers can be particularly vulnerable, especially the equipment located in cooler areas that typically aren’t prone to vicious heat waves that cause temperatures to soar to 100 degrees or even higher.

“When the temperatures are too hot, transformers in areas that are usually cooler can’t always handle unusually hot weather,” Smith said.

The transformer situation underscores the challenges that confront a utility whose service territories include foggy coastal areas, some of the nation’s largest cities, farmlands, mountains, deserts, foothills and interior valleys whose temperatures can gyrate over the course of a few months.

Plus, according to PG&E, the problem can’t be solved by simply using transformers crafted to withstand hellish Central Valley heat waves, deploying the hardy gear to the cool regions that are often swept by ocean breezes. Damp climes might be more likely to compromise transformers that are ideal for the Central Valley, PG&E said.

“You try to use the type of transformer that is appropriate for the weather of an area,” Smith said.

PG&E is under intense scrutiny in the wake of a string of catastrophes that have been linked to the utility.

In 2010, the company caused a gas pipeline to rupture, a disaster that killed eight and leveled a

San Bruno neighborhood. In 2016, the company became a convicted felon when a federal jury found PG&E guilty for crimes it committed before and after the deadly explosion.

In 2015, PG&E equipment failures caused a fatal wildfire that tore through parts of Amador and Calaveras counties, killing two people.

In 2017, a series of infernos scorched the North Bay Wine Country and nearby regions, killing 44. PG&E’s equipment was deemed to be the cause of 17 of the conflagrations.

In 2018, a wildfire roared through Butte County, a blaze that killed 85 and essentially destroyed the town of Paradise. State investigators determined this fire was caused by PG&E equipment failures. It’s the deadliest fire in California history.

On Jan. 29, facing a forbidding landscape of mounting wildfire claims and other liabilities linked to the infernos of recent years, PG&E filed for bankruptcy, listing $51.69 billion in debts, and seeking to reorganize its shattered finances.

The outages on Monday disrupted power for 14,600 customers in the East Bay, 5,100 in the South Bay, 4,300 in San Francisco, 1,800 on the Peninsula, and 600 in the North Bay, PG&E said.

PG&E said it is attempting to operate safely, but it appears that the transformer issue has no immediate or obvious remedy.

“Transformers are designed for the climate where they are installed,” Smith said. “When transformers are unable to cool down, they will fatigue and will fail.”